Who is accused LAX gunman Paul Ciancia?

Authorities are trying to determine the motive behind an armed man going to Los Angeles International Airport and fatally shooting a Transportation Security Administration officer.

The gunman, identified by the FBI as 23-year-old Paul Anthony Ciancia, entered Terminal 3 on Friday and pulled a rifle from his bag, killing Garardo Hernandez. According to the TSA workers union and federal sources, Hernandez was working as a travel document checker.

Witnesses say Ciancia calmly asked people, "Hey, are you TSA?" If they said "no," Ciancia would move on. Airport Police Chief Patrick Gannon said Ciancia got "far, very far back into the terminal," shooting two more TSA officers and a passenger before he was wounded and captured.

Ciancia was taken to the hospital after the shooting. FBI Special Agent in Charge David Bowdich said Saturday that Ciancia has been "unresponsive."

Ciancia has been charged with two felony offenses -- murder of a federal officer and commission of violence in an international airport. If convicted, he could face the death penalty.

A federal law enforcement official said Ciancia had material expressing anti-government and anti-TSA sentiment. The source said Ciancia also reportedly had material referencing The New World Order, which is generally considered to be a conspiracy theory in which people suspect a group of elites are conspiring to form an authoritarian, one-world government.

Authorities in Pennsville, New Jersey, said Ciancia's father contacted them after he learned of a text message sent by Ciancia to his younger brother on Friday. The exact details of the text message is not known, but authorities said it was alarming enough to suggest Ciancia wanted to hurt himself.

"Basically, the text message was just a message to the little brother and the way it was written, they had some concern about it," said Pennsville Police Chief Allen Cummings.

Pennsville authorities contacted the Los Angeles Police Department, who then went to Ciancia's apartment. Authorities found Ciancia's roommates, but they said they hadn't seen him since the night before and that he "was fine."

Cummings said Ciancia's family last saw him in the summertime when he attended a wedding, and they said he didn't show any signs of trouble or mental illnesses. Cummings said they also didn't know if Ciancia owned a weapon or if he had any anti-government leanings.

"I mean this is a shock to them. It's a shock to our community," he said.